Network connectivity issues or unresponsive interfaces

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Configuring multiple interfaces on the same subnet might cause certain interfaces to appear unresponsive or other network connectivity issues.

When you configure interfaces on the appliance, it is not advisable to configure IP addresses that span the same subnet across multiple interfaces. By default, the appliance validates that overlapping subnets do not span multiple interfaces., but such validation can be manually overridden if you choose to do so.

Having a single subnet that spans multiple interfaces is discouraged in general networking terms. The appliance environment is no exception to this rule. Configuring the same subnet on multiple interfaces causes the routing table to contain duplicate routes, one for each interface.

Diagnosing the problem

If some interfaces seem to become unresponsive or when the packet trace seems to capture traffic only on one side, you might consider this problem.

Resolving the problem

Preferred method

The preferred way to rectify this problem is to configure different interfaces to be in different subnets.

Alternate method

Note: This approach is not advisable if the appliance is being installed in the DMZ. Since the management interface and any reverse proxy instances have the same IP address, management services might possibly be exposed to the public.

Reverse Proxy instances can listen on all interfaces and do not need to be tied to a specific Application interface. It is not mandatory to configure Application interfaces on the appliance.

During configuration of a new Reverse Proxy instance, specifying 0.0.0.0 for the IP address of the primary interface ensures that the new instance listens on all appliance interfaces, including the Management interface.

For existing Reverse Proxy instances, the primary interface can be changed through LMI by selecting the instance, clicking Edit, and then modifying the values on the Server tab.

Note: When you change the network interface on which an existing Reverse Rroxy instance is listening, ensure that no other services are listening on the ports that are specified under HTTPS Port and HTTP Port. Otherwise, the Reverse Proxy instance might fail to start.

By default, ports 80 and 443 on the Management interface are used by the Local Management Interface. If a Reverse Proxy instance needs to listen on those ports, you can change the default port values that are used by the Local Management Interface through the Administrator Settings panel.